ceramic coatiings and surface engiineeriing

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Ceramic coatings and Ceramic coatings and

surface engineering surface engineering

Suranaree University of Technology October 2007

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p h o l

Chapter 1

• Friction and wear • Chemical corrosion

• Conductivity, insulation

• Reflectivity

• Thermal damage

Problems Protection of material surface

Surface engineering

Ex: Glasses, oxides, carbides,

silicides, borides, nitrides

Ceramic coatings (cermakrome) inside/outside for

exhaust manifold in Aston Martin

www.camcoat.u-net.com

Molybdenum coating on piston head

www.landyonline.co.za






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Chapter 1

Silicate glass

• On ceramic substrate glaze.• On metal surface porcelain enamel .

• On glass substrate glass enamel .

Porcelain enamel

Ceramic glaze

• Protect surface ( permeability)

• Spraying, dipping techniques.

Glass enamel

www.tias.com






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Chapter 1

Oxide coating • Provide oxidation resistance at high temperature.

• Provide corrosion resistance.

Using thermal or flame spraying techniques.

Cr 2 O 3 coating on Hastelloy C for use in

very corrosive envi.

Cr 2 O 3 coating on glass fibre-reinforced

polymer.






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Chapter 1

Carbide coating • Provide wear resistance due to high hardness

Thermal spraying of tungsten carbide-cobalt chromium coating (WC/10Co4Cr) on to a roll

for the paper manufacturing industry

Microstructure of WC/10Co4Cr coating






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Chapter 1

Nitride coating

CrN coating , HV = 1800, Tw = 700oC

TiAlN coating , HV = 3600, Tw = 850oC

TiN coating , HV = 2400, Tw = 500oC

• PVD technique

www.ijs.si/ctp/tin.jpg






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Chapter 1

Ceramics for energy

P-N junction

Doped with B, Al Doped with P

http://www.leonics.com

Solar cell

http://www.energy.go.th

www.corrosion-doctors.org/.../solarcell . jpg



Ceramics in biomedical Ceramics in biomedical

applicationsapplications


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Chapter 1

Alumina in orthopedic implants

a) Extensive arthritis damage, b) same hip

after total hip replacement

Various component for total hip prostheses

including the stem with an alumina femoral head,

and alumina AC cup, and a metal base for the AC

cup

• Excellent corrosion resistance

• Wear resistance

• High strength

• Biocompatibility

Co-Cr alloy femoral head with high

strength polyethylene cup (metal on

polymer)

Replaced by alumina (ceramic on

ceramic) to reduce wear particle

formation which causing loosening

of the prostheses.

99.8% Al, 3-6 µ µµ µ m grain size






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Chapter 1

Applications

• Orthopedic implants

• Eyeglasses

• Laboratory ware

• Dental applications

Bone joint

• Biocompatibility• Bond well to bone (implant-tissue attachment)

• Corrosion resistance

• High stiffness

• Wear resistance

Ceramic biomaterials

Implant loosening

Burden from healthcare cost

and patient’s life quality






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Chapter 1

Alumina in dental implants

The dental implant component

• Artificial root which supports toothreplacement and crown (porcelain).

• Titanium is also a good candidate

due to low modulus of elasticity and

biocompatibility.






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Chapter 1

Ceramic implants and tissue connectivity

Four types of responses from implant-tissue reaction

• Toxic

Tissue surrounding the implant dies

• Biologically inactive

Thin fibrous tissue forms around the implant

• BioactiveInterfacial bond between the bone and the prosthesis forms

• Resorption (Dissolving)

The surrounding tissue replaces the implant material or portions of it.



Nanotechnology and Nanotechnology and

ceramicsceramics


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Chapter 1

Nanotechnology and ceramics

Nanocrystalline ceramic Improving toughness ?

Nanosize powder (<100µm)

Agglomerates

Compaction 20-50% pore

Sintering and densification

Very quick due to nanosize

Ex: TiO2 (< 40 µµµµm)

98% theorectical density after 700

o

Csintering for 2 h.

Pore shrinkage through plastic flow (grain

boundary sliding) in nanocrystalline ceramics




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Chapter 2

www.umms.sav.sk

composite materialscomposite materials




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Chapter 2

What is composite material?

Structural material made of two or more different materials in a

macroscopic level.

A complex material, such as wood or fiberglass, in which two or moredistinct, structurally complementary substances, especially metals,

ceramics, glasses, and polymers, combine to produce structural or

functional properties not present in any individual component.

A structure or an entity made up of distinct components.

Structural materials can be mainly divided into four categories: metals,

ceramics, polymers and composites.





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Natural forms Artificial forms


Chapter 2





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Chapter 2

Composites

CMCs

MMCs

PMCs

Other

Al Composites

Ti Composites

Ni based alloy

Composites Steel

Composites

Carbon

CompositesWood

Composites

Resin

Composites

Cement

Composites

Polymer

CompositesGlass

Composites

Mg

Composites




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Chapter 2

Applications

Boeing 787 Dreamliner

Hockey stick made

from fibre-glass

tsa.imageg.net

www.nrc-cnrc.gc.ca




Matrices and Matrices and reinforing reinforing materialsmaterials


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Chapter 2

Composites

• Metals

• Ceramics

• Polymers

• Wood

• Fibres

• Filament

• Particulates

• Flakes• Globular

Matrix + Reinforcing materials

• Platelet

• Needles

• Woven

• Honey comb



Choices of reinforcing materialsChoices of reinforcing materials


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Chapter 2

• Reinforcing materials normally provide

stiffness, strength and sometimes

improved toughness.

• Mostly in the form of fibres,

• Properties are directly related to their

atomic arrangement and defect content of the reinforcements

(manufacturing process***).

• Reinforcing materials can be

polymers : Kevlar

ceramics : SiC, glass fibres

metals : steels fibres

Glass fibres

www.millipore.com

Single glass fibres

http://en.wikipedia.org

Steel



Different shapes of Different shapes of

reinforcing materialsreinforcing materials


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Chapter 2

Different shapes of reinforcing materials

• Fiber/filament (continuous or non-continuous)

• Woven

• Flake• Needle

• Aggregate

• Particulate

• Globular

• Platelet




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Chapter 2

1) Carbon fibres2) Boron nitride fibres

3) Glass fibres

4) Organic fibres5) Silicon carbide fibres

6) Alumina and aluminosilicatesMicrofilaments

MultifilamentsShort fibres

CVD monofilaments

PCS multifilaments

Whiskers

Fibres Particulates

1) Carbide particles2) Boride particles

3) Nitride particles

7) Nylon

Different types of Different types of


Ch t 2




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Chapter 2


reinforcing materialsreinforcing materialsCarbon fibres

Schematic structure of carbon fibres

Boron nitride fibres

sierra.univ-lyon1.fr

Tensile strength

Young’s Modulus

Density

2000-7000 MPa

250-530 GPa

1.75 g/cm3

A cloth of woven

carbon filaments

• Boron nitrides areextremely hard , only

second next to diamond

• Temp ~1000-1400oC

Ch t 2




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Chapter 2


reinforcing materialsreinforcing materialsGlass fibres

Glass fibres

www.vscht.cz

• Most are silica (SiO2) with addition

of Ca, Na, B, Al, Fe.

• Can be divided into electrical ,

corrosion and strength glass.

Organic fibre :Kevlar

or aramid fibres

• Kevlar fibres are long molecular chain structure of polymer (poly-

paraphenylene terephthalamide).

• E xpensive.

Kevlar fibres

www.fiber-tensioners.com

Kevlar

Chapter 2




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Chapter 2



Production of glass fibres

Continuous E-glass fibre production

www.jmeurope.com

• The raw materials are melted in

a reservoir and fed into a series of

platinum bushings, each of which

has several hundred holes in its

base.

• The glass flows under gravity andfine filaments are drawn

mechanically downward onto a

drum (at speed 2000-3000 m/min).

Chapter 2




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Chapter 2


reinforcing materialsreinforcing materialsSilicon carbide fibres

iar-ira.nrc-cnrc.gc.ca

1) CVD monofilaments

2) PCS multifilaments

3) Whiskers

4) Particulates

Carbon fibre

SiC

Whiskers

• Strongest reinforcing materials available

• Defect free, single crystal rods.

• 0.1-1.0 µm in diameter and 5-100 µm.

Tensile strength

Young’s Modulus

7.0 GPa

550GPa

fb6www.uni-paderborn.de

Ch t 2




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Chapter 2


reinforcing materialsreinforcing materialsCVD monofilaments

• Carried out in a reaction chamber by passing gaseous carbon

containing methyl-trichlorosilane

(CH 3SiCl 3).

Reaction chamber

http://sic.eng.usf.edu/cvd/www/

• The core fibre is heated (by passingelectrical current through it).

• The gas dissociates thermally at the

fibre surface to deposit the SiC .• Deposition of the second layer (graphite

or diamond) is subsequently applied in the

second reaction chamber to improve the

effects of interaction reactions withmatrices such as titanium.

Diamond coated SiC fibre

www.chm.bris.ac.uk

Chapter 2




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Chapter 2


reinforcing materialsreinforcing materials Alumina and

aluminosilicate

Nylon

Aluminium reinforced alumina short fibres

igahpse.epfl.ch

• Refractory

• Alumina and alumiosilicate

fibres can be divided into

multifilaments (FT TM fibre) or

short fibres (Saffil TM fibre).

• Nylon is a thermoplastic polymer

(polyamine) and generally used for

many applications.

• Strong, elastic and has abrasive

resistance.

Nylon

composite

sprocket

www.saffil.com

Chapter 2




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Chapter 2

Properties of different types of fibres

Chapter 2




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p



Particulates

Carbides

Borides

Nitrides

•Silicon carbide (SiC)

•Tungsten carbide (WC)

•Titanium carbide (TiC)

• Normally are in the forms of carbides, nitrides or borides.

Titanium nitride-Tinate (TiN)

Titanium boride (TiB2 )

SiC particles in Al matrix

• High Tm, high hardness, high wear resistance, low density.

Chapter 2



Choices of matricesChoices of matrices


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p

Polymers

• Plastics or resins are

the most widely used.• Lightweight.

• Easily fabrication.

• Low-moderate

temperatures.• Low-moderate strength

and stiffness.

• Also used for reinforcing

materials.

Metals

• Moderate to high

temperatures.• High strength stiffness,

moderate toughness.

• Moderate weight.

• Difficult to fabricate.• Also used for

reinforcing materials.

Ceramics

• Cements are the most

widely used.• Light-moderate weight.

• High temperatures.

• High strength and

stiffness but lowtoughness.

• Fabrication is not too

difficult.

• Also used for reinforcingmaterials.

• Matrix holds reinforcing material together and also determine

the physical properties of the end products.

Chapter 2




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Maximum service temperatures for different kinds of materials.

Specific strength of

advanced materials.

Choices of matricesChoices of matrices

Chapter 2




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MatricesMatrices – – Selected propertiesSelected properties

Chapter 2




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MatricesMatrices - - PolymersPolymers

• The most widely used due to cheap fabrication (low temp ~ 300-400oC).

• Lightweight applications such as aircraft, sporting goods, wheelchairs• Normally use carbon fibres as reinforcing materials.

• Thermosets: epoxy resin*, phenolic resin or furfuryl resin

Heat+pressurepolymerization with cross-link

Thermoplastics: polyimide (PI), Polyethersulfone (PES),

polyetheretherketone (PEEK), polyetherimide (PEI)

and polyphenyl sulfide (PPS).

Lower temp + better plasticity injection moulding

•

www.zyex.com

Epoxy resin

with tools

Chapter 2




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MatricesMatrices - - CeramicsCeramics

• Ceramic matrix composites

• Ceramic aggregate composites

• Reinforcing material (fibres) is added to improve its toughness

and strength (tensile and flexural).

• Good oxidation resistance high temperature applications.

Note:

• Concrete (cement)

• Cermet (ceramic and metal)

• Bone (hydroxyapatite reinforced with collagen fibres)

• Asphalt concrete

• Dental composite

• Synthetic foam (spheres of glass)

Chapter 2




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Cement matrix composite

Cement

Sand

Gravel

Admixture

• No sand and gravel cement paste

• Cement and sand Mortar

• Cement, sand and gravel concrete

Curing

(Hydration)

• Fine particulate such as silica (SiO2) fume or

polymer such as latex to decrease porosity.

• Short fibres such as glass, steel, carbon

Concrete is the most widely used

civil structural materials.

Fracture surface of

carbon fibrereinforced cement

enpub.fulton.asu.edu

322 ,,, O Al SiOMgOCaO

Chapter 2




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Dental matrix composite

• Cermet = ceramic (cer) and ~ <20% metallic (met) materials with

Ni, Mo, Co as binders for oxides, boride, carbide or alumina

• High temperature resistance and hardness.

Ex: Spark plugs for internal combustion engine, composed of a shell,

insulator (aluminium oxide) and conductor (Cu, Ni-Fe, Cr).Spark plug http://en.wiki

pedia.org

Cermet

Polymerizable dental

composite

polymers.nist.gov

Dental composite blocks

www.cereconline.com• Consist of resin based matrix such asmethacrylate resin and an inorganic

filler such as SiO 2 (silica) with a wide

range of compositions.

• wear resistance and translucency .

Chapter 2




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MatricesMatrices - - CarbonCarbon

C-C composite

http://www.composites-by-

design.com

• Highly-ordered graphite fibresembedded in carbon matrix..

• Strength and toughness superior to

conventional graphite.

• Stiffer, stronger and lighter than steelsor other metals.

• C-C composites consist of two brittle

phases but are very tough.

Carbon-carbon composites

• Oxidation problem at T > 320oC.

required SiC coating or glassy

sealant

↑→+ 22 COOC

honeycomb panels for

aircraft and helicopter

firewalls

Fracture of 2D C-C composite: two brittle

phases but high toughness.

Surface

energy

Fracture

surface area

BUT

Toughness

Chapter 2




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MatricesMatrices - - MetalsMetals

Note: Al, Mg and Ti are active with oxygen chemical reactions at the interface.

• Aluminium alloys

• Magnesium alloys

• Titanium alloys

• Nickel base alloys

• Steels

• Copper alloys

ewkmmc.tuwien.ac.at

SiC fibre reinforced intitanium matrix composite.

Chapter 2




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Metal matrix composites (PMC)Metal matrix composites (PMC)

Nylon steel composites

www.duragear.com

Copper clad steel trolley wires

in bullet train

www.fujikura.co.jp

www.afrlhorizons.com Ti/SiC reinforced bling in

aeroengine Rolls-Royce Plc.

www.isis.rl.ac.uk

Fibre-reinforced plastic

with Al laminates

www.compositesiq.com

Applications

Chapter 2




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Mechanics of compositesMechanics of composites

How many fibres we can put in to improve strength?

• Volume fraction of fibres

• Fibre arrangement

• Interfacial bonding between fibres and matrix

- Square array

- Hexagonal array

r

S

2R Square array

r

S

2R

Hexagonal array

785.0max = f V

907.0max = f V

Chapter 2




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σ σσ σ 1σ σσ σ 1

2

13

mm f f c V V σ σ σ +=

mm f f c V E V E E +=

Note: let c – composite

f – fibre

m - matrix

Longitudinal stress and stiffness

1=+ m f V V

Transverse stiffness

m

m

f

f

c E

V

E

V

E +=

1

σ σσ σ 2

σ σσ σ 2

2

1

3


Chapter 2




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Example: By assuming the law of mixture, and a square array of continuous

fibres, calculate the maximum and minimum moduli that can be achieved in

an unidirectional reinforced composite if seven fibre mm-1

is required for thedesign specification, the fibres are of 100 µ m in diameter. Given the modulus

of the fibre and the matrix are 450 and 120 GPa.

The volume fraction of fibres

( )( )

385.010

49105023

26

=××

==−

−π

c

f

c

f

A

A

V

V

The maximum modulus

GPa E

E

V E V E E

c

c

mm f f c

05.247

)385.01(120385.0450

=

−×+×=

+=

The minimum modulus

( )

GPa E

E

E

E

V

E

V

E

c

c

c

m

m

f

f

c

2.167

1098.51

120

385.01

450

385.01

1

3

=

×=

−+=

+=

−

Chapter 2




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Fabrication of compositesFabrication of composites

Compositemanufacturing

Nature of fibre and matrix

Fibre architecture

Fibre arrangement

Fibre volume fraction

Processing route

Manufacturing cost

The development in fabrication

process strongly affectscommercial exploitation.

Chapter 2




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Open mould

(spray-up)

Hot-melt prepregging process

Prepreg tapes

www.imhotepcomposites.co.uk


Chapter 2




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Machine for producing sheet-moulding compound

• Continuous fibres are

chopped and fed in the

middle of resin filler pastes (from top and

bottom) to produce a

form of sheet .

• The sheet is then rolled

for further compaction.

Sheet moulding compound

Chapter 2




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Premixed injection

moulding

Injection of thermoset premixed

Automated filament winding process

Filament winding

Chapter 2




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Resin transfer moulding

High speed resin transfer

moulding process

Chapter 2




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ceramic coatiings and surface engiineeriing

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